1. Field of the Invention
The present invention relates to an image communication apparatus which is capable of executing an image storage process to store image data for transmission into an image storage device, after compression, in parallel with a transmission process to transmit such image data for transmission stored in the image storage device, and further to an image communication apparatus which is capable of, in addition to such a parallel storage and transmission processing function as mentioned above, recording and outputting, after completing transmission, a report showing the transmission results and having attached thereto an image of the first page of an image for transmission, and more particularly to the manner of executing such a parallel storage and transmission processing function.
2. Discussion of the Background
When transmitting an original document of plural pages to a designated destination using an image communication apparatus such as a facsimile machine, a user generally has to wait beside the apparatus until transmission of the last page of the original document is completed to bring back the original document from the apparatus to his or her desk.
For eliminating such an inconvenience, a facsimile machine has been put to practical use which is capable of performing a so-called store and forward function to store image data of an original document of plural pages once into an image storage device and then originate a call to transmit the stored image to a designated destination. By utilizing such a store and forward function, a user can take out an original document from the apparatus once the scanning and storing processes have been completed and leave from the apparatus leaving the following processing to the apparatus, thus shortening the period of time the user is fettered by the apparatus and greatly enhancing the convenience of the apparatus as a result. Since the process of storing an image data of an original document into an image storage device and the process of transmitting the stored image data are executed one by one in consecutive order as illustrated by steps S10-S14 in FIG. 1, the period of time for completing a whole process of transmitting an original document is the sum of a time for storing the image data into an image storage device and a time for transmitting such stored image data.
Here, the storage process includes a process of reading an original document by a reading device, such as a scanner, a process of compressing an image data which is obtained from such a reading process and a process of storing the compressed image data into an image storage device. The transmission process is primarily made of a process of reading out the image data which is stored in the image storage device and transmitting the data to a destination station. Since each process executed in the storage process and the transmission process is a kind of process which is not repeated as described above, it is conceivably possible to execute the storage process and the transmission process almost in parallel. If the storage process and the transmission process are executed in parallel as illustrated in FIG. 2 (such a process hereinafter is called a parallel storage and transmission processing), the period of time required for transmitting an original document can be shortened by the period of time the storage process and the transmission process are executed in parallel.
As described above, a parallel storage and transmission processing has an advantage of shortening a transmission time greatly, and is effective if such a parallel processing is executed when the remaining storage capacity of an image storage device is large enough to store the whole portion of an original document for transmission. However, if such a parallel processing is executed when the remaining storage capacity of an image storage device is not large enough, there is a possibility of the image storage device overflowing while storing an original document, thereby disabling further storage of the image data and causing such an inconvenience that transmission is terminated in the midst of the transmission. Since a reading speed of a scanner and a speed of storing an image data into a storage device are becoming faster lately, there is a good possibility that a storage area of the image storage device is used up and transmission is terminated frequently in the midst of transmitting an original document even if a measure is taken for deleting an image data which has been transmitted from the image storage device.
For eliminating such an inconvenience, it is conceivable, for example, to hold an image storage process temporarily before image storage device overflows, and at the same time to delete image data which has been transmitted from the image storage device for increasing the remaining empty storage capacity of the image storage device, and to restart the storage process once the empty storage capacity reaches a certain level. However, if such an intermittent reading and storing operation is made, a case occurs that a scanner stops while reading a page of an original document and makes a restart. If such a case occurs, there happens a situation that an image data of a portion of an original document where the scanner has stopped and made a restart is disordered causing, as a result, deterioration of the quality of an image for transmission.